The recent emphasis on finding alternative energy sources to fuel the energy needs of the United States and the world is leading to an accelerated search for new fuels or new sources of fuel. Producing a liquid fuel from biomass, or biofuel, is an important focus of many alternative energy strategies. Ethanol production from plant biomass is one example of this. Another example of a newer fuel is biodiesel. Refined vegetable oils have been the typical starting materials for the production of biodiesel. Biodiesel is an alternative, non-toxic, biodegradable and renewable diesel fuel. These characteristics of biodiesel reduce the emission of carbon monoxide, hydrocarbons, and particulate matter in the exhaust gas compared to diesel fuel.
The production of non-alcohol biofuels from terrestrial and aquatic biomass primarily involves the conversion of trigycerides within the biomass to either fatty acid methyl esters by trans-esterification or to hydrocarbon-based fuels by various catalytic high-temperature processes which convert the oils to hydrocarbon-based fuels. Most of focus has been on the triglycerides. The conventional method for transesterifying the triglycerides to produce methyl esters, which can be recovered and marketed as FAME (fatty acid methyl ester) biofuel, is reaction with methanol in the presence of a base catalyst, usually sodium hydroxide, at temperatures not exceeding 100° C. In this reaction, the three-carbon backbone of the triglycerides is converted to glycerol (1,2,3-trihydroxypropane). Large-scale production of biofuel by this approach has and will lead to large excesses of glycerol that currently has very little value in commercial markets.